Sleeve-type carriers are typically formed from a blank which is delivered to a packaging machine in the form of a collapsed sleeve. The sleeve is erected or opened in the machine and articles are loaded through one or both ends of the sleeve, after which the ends of the carrier are closed. Formation of the end panels of the carrier normally requires the end panel flaps and the dust flaps to which the end panel flaps are glued to be separately folded into place by separate folding steps. While this process continues to be successfully employed in the packaging industry, there are certain areas which nonetheless could be improved.
It would be desirable to facilitate the closing of the end panels by providing a more automatic closing operation. It would also be desirable to have a carrier which is capable of more closely following the contours of curved packaged articles in order to more tightly hold the articles within the package. Normally, the end panels of a sleeve-type carrier form right angles with the side panels, which makes it difficult for the corner areas of the carrier to contact curved articles such as beverage cans and bottles.
An example of a more automatic end closure arrangement is disclosed in U.S. Pat. No. 4,747,487 which provides triangular webs for connecting the end panel flaps to the dust flaps or so-called closure flaps. The connecting webs cause the dust flaps to move into place when the end panel flap is moved from an open vertical position to its final closed position in the end of the carrier. In addition, separate triangular corner panels are provided between the side panels and the closure flaps. The angles formed by the corner panels with both the side panels and the closure panels are greater than 90.degree., which enables the corner area of the carrier to conform to a curved surface more readily than the usual right angled corner configuration of conventional sleeve-type carrier designs.
Although the patented carrier is an improvement over conventional designs in the areas discussed, it would be desirable to further improve certain features of the carrier. The connecting webs are not always conducive to easy closure of the end panel flaps due to the thickness of the various folds of material in the end corner areas. Also, the triangular corner panel arrangement does not provide the desired degree of contact with the surface of curved articles. It is therefore an object of the invention to provide a sleeve-type carrier that improves upon the performance of prior art carriers in the areas discussed.